New build...

ONLY for ADVANCED technical discussion about the 240sx!
xnizstudio
Posts: 6
Joined: Tue Jun 23, 2020 2:07 pm
Car: 2004 Nissan 350z
2009 Nissan 370z
1993 240SX

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Sooo I drive a 370z as my daily..I have a 350z as well. I also have a turboed 99 Miata I'm almost done building for drift. Recently I picked up a 240sx shell for about $1500 (talked the guy down) for Fathers Day. Shell came with new paint, aftermarket wheels and body kit. No engine or transmission.

Interior was gutted but I still have all the parts. I'm going to do a street build with my dad.

Now... here is where I piss everyone off. I'm dropping a Chevy 350 SB in it with automatic turbo trans. Aluminum corvette heads to reduce weight. Engine is fully built with flat top pistons, ARP head studs, etc and board over from the machine shop. Along with that, will be purchasing a serpentine chrome conversion kit to retain power steering and AC.

My dad is a mechanic and can build / fix anything. I've already been doing research on this particular type of build. My dad has been wanting to do it since 2009. So for Fathers Day I bought him the shell. He can also weld and do fabrication as needed. The only thing we need is to buy a lift for the drive way and a pipe bender. We need a lift because he's getting too old (lol) and to help fix any rust underneath.

Some things I know I will need to do is:

1) Cut some of the firewall out to move the engine and transmission back as far as possible and closest to the firewall as we can to help with weight distribution. We want it to be street legal but also want to be able to drift for fun if needed. When drifting, I know too much weight on the front can be good and bad. Good because it lifts the rear end, but bad because it affects the steering making it harder to control.

2) Replace entire rear end and custom drive shaft. My dad was thinking of 4 link suspension on the rear (might convince him to bag it, who knows). The rear end suspension and sway bar has quite a bit of rust with regards to the suspension and hub assembly. The frame itself seems solid. So the entire rear end is getting replaced, for sure.

3) Hoping I can create my own wire harness or use part of the old harness to keep most of the electronics working (radio, headlights, etc). Anything related to the engine will prob be zip tied off out the way or removed completely from the harness. (engine connectors, sensors, etc). The main thing is retaining the headlights, brake lights, turn signals, windshield wipers, etc... the windows are manual, so no need to worry about power windows at least.

4) Oil pan will need modification to make the engine fit. I found that the oil pan should match one in this video: https://www.youtube.com/watch?v=pUceFyT3ICA . We will probably find a similar oil pan online and cut/re-weld it for fitment.

5) Probably a hole cut in the hood for the carb to stick out a little and will just cover the hole with a nice scoop

6) For brakes.. probably gonna use some Brembo z33s or just stock z33 brakes. Not looking to spend $1000 just on brakes.

7) Racing fuel cell in the trunk with aftermarket fuel pump

8) Gotta throw a spoiler on the back

The block we have should be putting out about 350-400HP at minimum with the mods we have done to it. Possibly more. It was in a weight reduced cutless and lifted the wheels on take off.

I guess my main concern is mainly with the suspension. Since the block is a bit heavier than the KA24 fully dressed, would standard coil over suspension work? Or would I need to get some BC Racing coil overs with upgraded springs or upgraded struts (assuming we don't use 4 link suspension kit or bag the car out).

For the rear end... I'm thinking my dad will get a driveshaft and rear-end from a Camero or older Corvette and modify the length and put an entire new rear end in with posi / LSD. Not sure what type of gear he will go with, but its only a 4 speed (maybe 3 speed?) turbo auto trans. I'm gonna try and convince him to use a 5 speed manual instead since the car is already set up for manual, and I want it to have a clutch in case I do decide to do some drifting.

Anyways, his job is to handle the mechanical and custom fabrication side of things, while my job is to handle interior and electronics. I'm gonna use this project car as a way to learn more about wiring diagrams and upholstery. We're going with 2 buckets seats in the front with 3 point harness at minimum and probably a 4 point cage at minimum as well. Then the back of the car I want to install the stock interior back seats and reupholster the seats with black leather to match the black bucket seats. Same thing for the door panels. I want to remove the crappy cloth from the door panels and put matching leather. Probably need a heat gun to make it fit. Will use pleather / vinyl probably for the door panels.

I don't care to hear about how this is "a stupid idea". I make plenty of money and have no wife and no kids. I don't care how much this build will cost. I'm estimating 12-18 months to finish the build once we actually start it ( 4-6 months from now). So prob a year or so before it is 100%.

We already have the engine and transmission. From here its just handling the rear end/driveshaft and getting the interior and electronics working properly. Even if I had an SR20 or RB imported with the transmission, I'm looking at $3000+, and I will still need to tear it down and rebuild the engine and transmission before I feel safe installing it in the shell. Rather than waste time and money on the SR or RB import, I can get GM parts super cheap in any auto part store and online.

I'm only here to ask for some advice on what type of things to look for fitting the engine and transmission in the car itself and help with weight distribution. I've found a handful of 350 SBC posts on a few sites with a handful of tips i will be using.

I'm also attaching the picture of the shell I picked up. It's absolutely beautiful. I believe it is the Z1 Corvette Cybermetallic cide. professionally painted. The paint alone was almost $2000 and warrantied. Has 17 inch aftermarket wheels as well. (need restoration, but will be nice). i got the guy down from $3000 to a fair price I think.

The car is being towed to my house at the beginning of the month and I'm gonna finish gutting the entire inside and start preparing the inside of the for paint/heat protection as well as prepping the engine bay for paint.

I'm purchasing the following serpentine conversion kit: https://www.amazon.com/Chevy-Small-Bock ... B01D0L81RE . We have a guy who will be able to make the stock 240sx AC lines work with this kit, and I'm sure we can get the power steering to work as well. The block will probably be painted black, intake would be aluminum and the rest chrome. It's gonna be pretty under that hood.

With regards to the dash cluster, we're just going to do our own metal cut out, paint it black, and use aftermarket AEM gauges. The rest of the interior will be stock.

Anyways, any tips/advice would be cool. Any negative feedback, well I'll probably ignore entirely. My dad is an old school hot rod guy and has built plenty of 350 SBC engines and had them in Cameros, Cutlesses, Chevy S10 trucks, etc. He's always been a drag racer but he wants a nice street car with power that we can repair for cheap when it breaks. SR20 and RB engines... the parts are expensive and hard to come by unless you special order them. And he always wanted a Frankenstein 240sx. Since we have the 350 laying around...it's time to put it to use. He really wanted a 280z but I couldn't find him one for a good price.

Thanks in advance.

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AZhitman
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Joined: Mon Apr 29, 2002 2:04 am
Car: 58 L210, 63 Bluebird RHD, 64 NL320, 65 SPL310, 66 411 RHD, 67 WRL411, 68 510 SR20, 75 280Z RB25, 77 620 SR20, 79 B310, 90 S13, 92 SE-R, 92 Silvia Qs, 98 S14.
Location: Surprise, Arizona
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No hate here, sounds like a cool project. Anytime you can find a clean S-chassis shell for under $3500, it's a score.

I'll chime in more later (as I'm sure others will), but don't sweat the little bit of extra weight. I'd certainly prefer an aluminum block LS, but you work with what ya got. Coilovers (one of our staff is a BC vendor) will handle that fine.

Hoping the rust isn't problematic. Can't imagine someone putting a nice paint job on a car with underlying rust issues, but I'm a Datsun restorer - I see rust, I turn and walk away. :)

Good luck, and keep us posted!

xnizstudio
Posts: 6
Joined: Tue Jun 23, 2020 2:07 pm
Car: 2004 Nissan 350z
2009 Nissan 370z
1993 240SX

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AZhitman wrote:
Tue Jun 23, 2020 10:39 pm
No hate here, sounds like a cool project. Anytime you can find a clean S-chassis shell for under $3500, it's a score.

I'll chime in more later (as I'm sure others will), but don't sweat the little bit of extra weight. I'd certainly prefer an aluminum block LS, but you work with what ya got. Coilovers (one of our staff is a BC vendor) will handle that fine.

Hoping the rust isn't problematic. Can't imagine someone putting a nice paint job on a car with underlying rust issues, but I'm a Datsun restorer - I see rust, I turn and walk away. :)

Good luck, and keep us posted!
Yeah we found rust in the rear of the car but i think its mainly from sitting too long. The subframes and frame itself seemed okay from what we seen. The trunk has a good sized hole in it though. We're gonna be cutting it out and welding the fuel cell in its place anyways. If anything, my dad is crafty. We can work on surface rust as long as the frame isn't rotted out.

The guy I got it from said he bought it from Maryland and the guy had an SR20 in it but the block was cracked. As he had the car in the paint shop getting painted, he started rebuilding the SR20 and found the block was no good. Decided to sell the shell to try and re-coup some of the money he spent on the paint.

I'm hoping the rust isn't too bad, but my dad said its mainly just the suspension and some of the under carriage panels, not the frame. So if we gotta do some cutting and welding, it would be worth it. Worse comes to worse... I find a cheap 240sx for less than a $1000 thats beat to s*** with a good frame, and we pull the frame from under the chassis and swap everything over (if thats even possible). Either way, I bought the car and I'm stuck with what I got for now.

I think it's gonna work out though...I can't wait to get it started and learn more about wiring and upholstery. I just learned how to rebuild my Miata 1.8 with my dad so I learned enough about engines for a little while. I'm definitely gonna get pictures and post updates as I go along.

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AZhitman
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Posts: 71063
Joined: Mon Apr 29, 2002 2:04 am
Car: 58 L210, 63 Bluebird RHD, 64 NL320, 65 SPL310, 66 411 RHD, 67 WRL411, 68 510 SR20, 75 280Z RB25, 77 620 SR20, 79 B310, 90 S13, 92 SE-R, 92 Silvia Qs, 98 S14.
Location: Surprise, Arizona
Contact:

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Yeah, there's no frame. An S-chassis is a unibody car (like your Miata). The tub (or shell) sits on a removable front and rear subframe.

Good luck - You're learning the right way!

xnizstudio
Posts: 6
Joined: Tue Jun 23, 2020 2:07 pm
Car: 2004 Nissan 350z
2009 Nissan 370z
1993 240SX

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AZhitman wrote:
Tue Jun 23, 2020 10:57 pm
Yeah, there's no frame. An S-chassis is a unibody car (like your Miata). The tub (or shell) sits on a removable front and rear subframe.

Good luck - You're learning the right way!
Oh okay... well the sub-frames were in good shape. Anything else, I'm sure we can repair (hopefully)

xnizstudio
Posts: 6
Joined: Tue Jun 23, 2020 2:07 pm
Car: 2004 Nissan 350z
2009 Nissan 370z
1993 240SX

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Just bumping the thread for any other advice! Thanks guys !

xnizstudio
Posts: 6
Joined: Tue Jun 23, 2020 2:07 pm
Car: 2004 Nissan 350z
2009 Nissan 370z
1993 240SX

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So... My dad thinks we need to rip out the entire rear end and put a GM rear end in the s13 because he thinks the 350SB is going to snap the axles or blow the rear diff the first time we do burn outs or dough nuts.

So I'm just googling around and searching, and it seems the z32 VLSD is the best route to go to handle power above 300-400HP and higher torque coming from the 350. Can anyone correct me if I'm wrong?

If I am wrong, what alternative route can I go? I know there are plenty of s13s that are putting down 500-600HP in the drift world... so what rear end axles and diffs are they using? I'd like to keep the rear end somewhat stock (Nissan fitted anyways). EDIT: I found these: Driveshaft Shop 500HP Rear Axle Bar Upgrade - Nissan 240SX 89-98 on Enjuku's website. So this may be a good start for the axle upgrade.

The driveshaft from the transmission to the diff/rear end will be custom fabricated (pretty easy to do once we get it on a lift and take measurements). So putting the engine in the bay, mounting the engine and transmission and running the driveshaft is the least of my worries.

I am more concerned with having a rear end that can hold up to a semi built 350SB. AFAIK, the block we have should easily put out 300+ HP with aluminum vette heads and flat top pistons and upgraded internals. I'll also probably be buying carburetor upgrades and a new / stronger fuel pump.

I really don't want to go ripping apart the rear end. Can someone advise me on a set of axles and differential that can withstand 400+ HP if needed with heavy torque? That way I can still use bolt on aftermarket parts for an s13 chassis for the rear end suspension.

I went ahead and purchased this for my "cluster": https://www.ebay.com/itm/240SX-S13-1989 ... 2749.l2649

This will allow us to use generic GM gauges but still have a nice clean looking dashboard.

The only other mods that come to my mind at this current time that is important to me is just a brake upgrade kit and possibly camber kits to control camber in the front and back of the car. For brake upgrades, any suggestions/kits that are known to be good but on a budget? (I dont want to spend $1000 on front/back brake upgrade kits if i dont have to). Most of the upgrade kits im finding though are about $400 a piece (front/back), totaling close to $1000. I also found guys doing z32 brake upgrades so I'm not sure if those are any better than the stock s13 brake or not. We don't want to put a ton of money in this car the first year of the build, so I'm just trying to keep it on a budget for now even though I have money, I just prefer to save where I can. So.... any budget "big" brake upgrade kits out there, or are the z32 brakes better than the stock 240 brakes, and are they the cheaper alternative to a big brake upgrade kit?

We plan on keeping it street legal and occasionally drag racing it and possibly drifting in the future. (hes the dragger, im the drifter).

Anyways... I'd like to know what you guys think for the rear end and what I can do to keep it from falling apart. I've been doing research but theres so many forum posts and I dont even know whats true and whats not. Some people say use the 32z rear end/axles and diff, others say to use the stock axles. But I definitely don't want to snap an axle and waste $$ on a tow home. Same thing for brakes... people say, use the z32 brakes etc.. So I'm just not sure what to believe. (Trust me, I don't want to be spoon fed), but I want to do things safely too.

On a good note, I inspected the car the other day and all the original interior is in the car (disassembled, yayyy).... so when I get the car towed home this weekend, my first business is to get everything out of the car... clean the inside out and wipe all the metal and maybe wetsand the entire inside body and start painting it. Theres some kind of paint you can spray inside the car under all your interior that helps reduce heat (I forget the name). But im gonna go pick up a spray gun ASAP and my first goal is to wet sand the interior metal inside the car and paint it front to back. Then put a new carpet mold in and start re-assembling interior and see what happens. Most of the interior looked to be in pretty decent condition (not many scratches etc, and the ones with small scratches I can always fix with a scotch bright pad / high grit wet sand and some interior paint, depending on the piece).

The only missing interior is the seats... I was thinking of putting some NRG bucket seats in there with 4 point harnesses (https://www.ebay.com/itm/NRG-FRP-Bucket ... Swtnhe3uiC)

My concern is the NRG FRP-300 seats aren't FIA certified so if i wanted to drift/drag race.. would I be able to? Or is it only certain tracks that require FIA certified seats? If so, I may need to save up and go with the cheapest set of FIA certified I can find...

Oh.. and we decided we're going with green color scheme. So... the gold wheels are going to be sand blasted, resurfaced, and painted green. Interior accents will be green. Under the hood, the engine block will be green with chrome kit. Possibly some other things under the hood will be green too if we can find it (maybe green spark plug wires, etc). It's going to be a sweet car when we're done and I plan on posting updates here every time we work on it. (Pictures, videos etc).

Finally, ona. side note, not related to my nissans, but here is my Miata (it's almost complete). Its got a small oil leak we gotta fix on the oil pan. Needs new tires and the rims to be painted. Then a coilover kit and my turbo needs installing. I got about $3000+ in my turbo kit. Most of the turbo is all bolt on stuff from CX Racing, and some are more expensive aftermarket parts (Megasquirt, Mishimoto intercooler, upgraded BOV, I forget which one exactly, but its nasty sounding).

The color code is "Caviar" from 2015 Jaguar paint book. It's like black in the dark, but when the sun hits it, it turns purple. This is my future drift car (still got a ways to go, but its getting there). I know the Miata rear ends like to kick out alot, but I've been practicing in the rain and snow when it snows during the window and I'm pretty good at keep it from spinning out.

Image

Cheers and thanks for any advice.
Last edited by xnizstudio on Sun Jun 28, 2020 9:54 pm, edited 1 time in total.

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AZhitman
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Posts: 71063
Joined: Mon Apr 29, 2002 2:04 am
Car: 58 L210, 63 Bluebird RHD, 64 NL320, 65 SPL310, 66 411 RHD, 67 WRL411, 68 510 SR20, 75 280Z RB25, 77 620 SR20, 79 B310, 90 S13, 92 SE-R, 92 Silvia Qs, 98 S14.
Location: Surprise, Arizona
Contact:

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A few thoughts:

Wall of text tells readers you're more interested in telling than listening. That's all well and good if you've finished a project, but you've not started. ;) Just a word of wisdom from someone who's been there and done that.

OK, with that out of the way:

If Pops wants a solid axle rear end, let's hope he's an engineer. An R200 diff is more than sufficient for a SBC (my turbo KA made twice the power and torque that iron block engine will ever make). I realize (as a fellow old guy) that'll cause some consternation, but it's a fact. There's no need to reinvent the wheel. Yes, a Z32 / Q45 has the R200 diff (and axles) you seek, and some searching on the topic will help immensely.

Z32 brakes with proper rotors and pads are fine. Tires are always the weak link. Rule of thumb: If you can lock the brakes up, you don't have enough tire. Z32 axles are fine as well, and they'll allow for a 5-lug upgrade.

If you're concerned about a seat certification,. you need to make sure the entire build is in compliance with whatever series or sanctioning body you think you're going to race under, which means you need to download their tech specs and inspection rulebook. I don't think this is that kind of build, so dial it back and remember you're building a street car that might see the track eventually.

NRG seats are Chinese junk, and harnesses are not for street cars. You've got some reading to do there as well (no spoon-feeding!)

Plus, you're talking about carpet and interior, which doesn't jive with that type of build. Build what you want and son't worry about a seat certification. Lots of fast, fun cars have stock seats and seat belts (I love first-gen Miata seats and have used them in three prior builds). :)

Carry on!

xnizstudio
Posts: 6
Joined: Tue Jun 23, 2020 2:07 pm
Car: 2004 Nissan 350z
2009 Nissan 370z
1993 240SX

Post

AZhitman wrote:
Sun Jun 28, 2020 9:45 pm
A few thoughts:

Wall of text tells readers you're more interested in telling than listening. That's all well and good if you've finished a project, but you've not started. ;) Just a word of wisdom from someone who's been there and done that.

OK, with that out of the way:

If Pops wants a solid axle rear end, let's hope he's an engineer. An R200 diff is more than sufficient for a SBC (my turbo KA made twice the power and torque that iron block engine will ever make). I realize (as a fellow old guy) that'll cause some consternation, but it's a fact. There's no need to reinvent the wheel. Yes, a Z32 / Q45 has the R200 diff (and axles) you seek, and some searching on the topic will help immensely.

Z32 brakes with proper rotors and pads are fine. Tires are always the weak link. Rule of thumb: If you can lock the brakes up, you don't have enough tire. Z32 axles are fine as well, and they'll allow for a 5-lug upgrade.

If you're concerned about a seat certification,. you need to make sure the entire build is in compliance with whatever series or sanctioning body you think you're going to race under, which means you need to download their tech specs and inspection rulebook. I don't think this is that kind of build, so dial it back and remember you're building a street car that might see the track eventually.

NRG seats are Chinese junk, and harnesses are not for street cars. You've got some reading to do there as well (no spoon-feeding!)

Plus, you're talking about carpet and interior, which doesn't jive with that type of build. Build what you want and son't worry about a seat certification. Lots of fast, fun cars have stock seats and seat belts (I love first-gen Miata seats and have used them in three prior builds). :)

Carry on!
I appreciate the feedback. I would disagree when you say I'm more interested in telling then listening. I'm more interested in learning. I do understand your perspective though. But I am also a very fast typer and I put a lot of thought into my responses. Me and pops just finished the Miata rebuild and I learned A LOT about 4 cylinder engines and rebuilding them using rebuild kits. (I can do my own timing now, head cylinder replacements, etc). I just like to try and be as informative as I can. Now I'm going from a 4 cylinder build into old school "muscle" car engines. Haha.

I edited my post, and I found Driveshaft Shop 500HP Rear Axle Bar Upgrade - Nissan 240SX 89-98 on Enjukus website. So I'll have to do research if its cheaper to run with these or the z32 axles. I'll also look into the R200 diff and put it on my list.

NRG seats, I assumed would be junk for the price. I may even go stock seats like you said and just reupholster them including the rear seats and have them all black vinyl/leather with green accents.

I think the aftermarket wheels I have may allow for 5 lug setup but I'm not 100% on that. But IIRC, they do, which would be great for the z32 swap if i go that route.

With regards to the interior, carpet and interior, my dad wants a bone stock interior 240sx (with exception of maybe bucket seats) but with a 350 under the hood, and I also want the same.

And pops is quite the innovator. Hes been a mechanic his entire life and also welded professionally for years. So he can definitely do some crazy stuff.

With that being said, I'll do more research on the z32 modifications and the R200.

I really appreciate the help. Thanks a ton. Seriously!!!


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